The distribution of the species la quite remarkable. Only one species (Spongia officinali.9 [adriatica]) is found OD the E. shore of the Adriatic and coast of Greece+, from Trieste to the Bay of Nauplia. From Nauplia and the island of Candia to Eritra, on the coast of Asia Minor, two occur, S. officinalis and S. agaricana [Zinlocoa]. Frorn Eritra, opposite the island of Chios, to Tripoli, all three, S. offici nalt,, S. agaricana, and S. equina, are fished, except at the ialand of Cyprus, where the zimocca sponge does not live. From Tripoli to Tanis, two only occur, S. officinaUs and S. cquina ; and from thence to Ceuta, at the Straits of Gibraltar, a very peculiar dark-coloured and coarse variety of S. equina 18 obtained, called the Gerbis (Gerba) eponge. The dealers have thus to do with a vast variety of forms. They cam however, pick out the three epecies and their varieties without hesita tiou, being led mainly by the general aspect of the surface. This has a distinct appearance in every species, and, though much altered by the greater or less development of superficial tufts, is much more constant than any other character. This is due to the fact that the surface takce its aspect largely from the nmuber, distribution, and size of the pores, cloacal orifices, superficial canals, and primary fibres. These characteristics, of course, are directly correlated with all that is important in the internal anatomy of the animal, and should therefore be more constant than the length, form, or composition of the tufts of fibres, or the shape of the whole, which are capable of great modifica tion, according to the locality in which the specimen may be found. The forms of S. officinalis may vary from eup-shape to flstular, and to irregular or lump-like. The latter are usually coarser and looser in texture, the superficial tufts are longer and more numeroua, and they approximate more closely to the coarser varieties of sub-sp. tubulifera of the Caribbean Sett, in the external aspect of the surface and the apertion of the interior, than the finer varieties. The texture of the poorest variety of the Mediterranean sponges is, however, always better for domestic purposes than the best of the corresponding American varieties, being firmer and more elastic ; and it is also to be remarked that the latter never have the cup-shape, which ie so common in the sub-sp. mediterranea, and that the fistitlar form takes its place. The forms of S. agaricina, sub-sp. Zimocca, vary from saucer-shape to irregular lump-like growth. As in S. officinalis, it may be shown that these aberrant forms are quite eimilar to the aberrant or formless varieties of the sub-sp. pun,ctata of Florida, as regards the aspect of the surface; but these also are nevertheless much finer than the finest varieties of the latter. Here, again, the platter- or saucer-shape, which is a n3odification of the cup-shape, is absent. S. equina exhibits similar degrees of variation in the texture of the surface and the form. There are no proper cup-sbaped specimens among the American varieties of sub-sp. gossypina, but, in place of these, the fistular form. These occur generally associated in clumps, more or lev:s densely filled up into heads, and eolid; but sometimes the tubes ara almost isolated. The younger specimens of this species have a very loose and open texture, due to the approximation and large size of the openings, and, to a less degree, this is also to be remarked in the Gerbis sponge. The former approximate in aspect to the coarser qualities of the American species ; so also does the latter, which has very nearly the same colour and aspect as the dark-coloured Key West specimens, but it is not so coarse and dark. It seems, then, that there are three sub-species of commercial value in the Mediterranean, which find their way into the New York and European markets. The coarsest varieties of the European sponges are finer, firmer, and more elastic than the finest of the corre sponding American sub-species. This is directly traceable to the larger amount of foreign matter included in the primary threads, and the looser mesh of the tissue ; the fibres are also comparatively coarser, and the large cloacal channels more numerous throughout the mass. The shape does not necessarily correlate with a finer or coarser skeleton, but probably with a more or less extended base of attachment, and with local peculiarities, such as currents, the kind of bottom, Ste., which have not been investigated in this connection.
Sponges always grow on hard surfaces—rock, coral reef, bricks, the barren stems of sea plants, &c. They are sought for in shallow water by the aid of a water-glass, which is a tube of thin boards or iron pipe several feet long, with a pane of glass at one end (often merely a, bucket with a glass bottom), which, when submerged, prevents the sight of the fisherman being disturbed by the glare of the reflecting surface and by its incessant motion. The latter obstacle alone is sometimes over
come by simply pouring oil on the surface of the water. When found, they are dislodged either by divers, or by so-called " harpoons." The divers descend either naked or in special dresses. When naked, they are carried down by a block of stone weighing some 25 lb., held at arm's length in front. The usual depth is 15-20 fathoms ; but some divers successfully reach 40 fathoms, after inflating the chest for about 10 minutes. The ordinary duration of a dive is 1-2 minutes, and 3/ is the maximum. The use of the harpoon, a kind of fork on a thin pole 3-6 fathoms long, dispenses with diving; it is used for the coarser Mediterranean and most of the Caribbean sponges, which grow in shallow water, and are not worth the risk and trouble of diving. A third plan is by dredging with a drag-net, whioh tears up the sponges and collects them in a bag behind.
About 12 hours' exposure to the sir suffices to kill the sponge. Subsequent oplations are designed to free the skeleton from the animal's remains. In the Mediterranean, as soon las the first sign of putrefaction makes its appearance, the sponges are tied to strings and k-neaded in sea-water with sticks or with the feet, till the " milk " or sarcode and the skin are quite removed, the latter being sometimes scraped off with a knife. This is performed much more rapidly in warm than in cold weather. Sponges should always be washed if possible within 24 hours of their capture, never being so good if left till the next day. When perfectly clean, they are dried by exposure to the sir, and then packed in bales. If packed before fully dry, they heat and become spoiled, assuming an orange-yellow colour ; partial remedies for this have been found in the weak acids, as citric, and in alkaline solutions. Sponges may be bleached by sulphurous acid, or by Blondeau's recipe, which is as follows :—They are flrst washed in warm water, and then in a solution con taining 0.5 per cent. of hydrochloric acid, to'remove the carbonate of lime ; the actual bleaching is effected by a 24 hours' immersion in a, bath containing 5 pints hydrochloric acid, and 6 pints hyposulphite of soda, in 100 pints water. This is said to be a more effectual and rapid process. But all bleaching must be at the expense of the durability of the sponge. In America and the Bahamas, want of care marks the conduct of the operations, the " killed" sponges being cast into pens formed by stakes driven into shallow water, called " crawls," and left to decompose fiS they may. They are finally squeezed, washed, dried, and sun-bleached. In the S. Pacific, much the same method prevails, the sponges being suspended from a light framework, so that they are washed by the tide when up, and exposed to wind and sun while the tide is out.
The chief localities of sponge-fishing cited by Eckhel are as follows ;—The bays of Patras, Corinth, Koran, Marathonisi, Nauplia, Kranidi, Budrum ; the islands of Cerigo, Hydra, Spezia, Poros, Salamis, Astrupala, Samos, Pathmos, Leros, Nisseros, Kalymnos, Symi, Chalki, Rhodes, Candia, Cyprus ; on the W. coast of Asia Minor, the localities of Chcsme, Eritra, Samos, Mendelia, Dschavata, 1VIktkry ; on the Syrian coast, Latakia, Tarabulus, Ruad Island, Batrun, Dschebel, Beyrout, Caiffa, Jaffa. ; the Straits of the Dardanelles, and the Sea of Marmara. The " harpoon" fishing is carried on chiefly at Nauplia, Kranidi, Hydra, Spezia, Agina, Poros, and Salamis, while the divers affect Symi, Kalymnos, Chalki, and Castell-rosso. Eckhel further classifies the 3 species into the following commercial sorts :—(A) Dalmatian : (1) Istria, (2) Dalmatia ; (B) Patras or Gulf ; (C) Greek : (1) Koran, Marathonisi, and Cerigo, (2) Nauplia, Kranidi, Hydra, Spezia, 1Egina, Poros, Salamis ; (D) Turkish: Volo, Trikeri, Argalesti ; (E) Bugaso : Dardanelles and Marmora ; (F) Astrupalia ; (G) Island : (1) SaMOS, Pathmos, (2) Leros, Nisseros, (3) Budrum, (4) Kalymnos, (5) Symi, (6) Chalki, (7) Rhodes, (8) Castell-rosso ; (H) Kankava : Chesme, Eritra, Samos, Men delis, Dschovata, Makry ; (I) Camdia ; (K) Karamanis ; (L) Cypria.n ; (M) Syrian : (1) Latakia, Ruad, Tripoli, (2) Batrun, Dschebel, Beyrout, Caiffa, Jaffa ; (N) Mandrucha or Barbarian : (1) [Katomeri] Arabian Gulf, Gatta Gulf, Mellach, (2) [Panomeri] from Melia to Derna, (8) Bombn, Tobruk, Ras-et-Tin, Tunia; (0) Bengazi ; (P) Gerby or Sfax : Tunis ; (Q) Red Sua ; (R) Bahamas.